JP2002340964A - Connection inferiority detection device in connection of flat cable and connection terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connection inferiority detection method in the connection of a flat cable and a connection terminal for detecting connection inferiority on the basis of the analysis of load behavior in the connection process of the connection terminal. SOLUTION: When a crimp piece 8 is thrust on the flat cable 4, the thrust load to a thrust displacement amount of the crimp piece 8 is measured, the minimum thrust load in a displacement area after the maximum thrust load is compared with the normal minimum thrust load, and the propriety of the connection state of the crimp piece 8 and the flat conductor is judged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a connection failure between a flat cable and a connection terminal.

[0002]

2. Description of the Related Art Conventionally, a method of connecting a wire and a connection terminal to connect between wires of a wire harness used for electrical wiring of an electric device or an automobile or connecting a wire to a device is to use a round wire. Crimping and crimping the connection terminal,
A method is used in which an insulated wire is inserted into a blade-type terminal, the insulating coating is broken by the blade-type terminal, and the terminal is brought into contact with a conductor.

[0003] As a method of determining the crimping state and the press-contact state of these connection terminals and conductors, Japanese Patent Application Laid-Open No. 63-281071 discloses a method.
No. and Japanese Patent Application Laid-Open No. 10-125439,
In both cases, the poor connection between the wire conductor and the connection terminal is determined by comparing the crimping or crimping load pattern against the time axis with the change in the crimping or crimping load pattern with respect to the time axis. ing.

On the other hand, in addition to the crimping and crimping methods for connecting the wire conductor and the connection terminal, in recent years, as the density of the wiring and the miniaturization of the connection terminal progress, as shown in FIG. Is 0.15mm ~ 0.2mm, width is 1.5mm ~ 3.0m
A flat cable 4 in which a flat insulating coating layer 2 of a polyethylene terephthalate film having a thickness of 0.09 mm is adhesively coated from both sides through an adhesive layer 3 on a plurality of flat conductors 1 having a length of about m, as shown in FIG. As shown, the terminal width W is 1.2 mm or more integrally with the mating connection portion 6 as the connection terminal 5.
A plurality of crimp pieces 8 protruding from both sides in the width direction of the 2.3 mm plate-shaped terminal portion 7 are pierced at the flat conductor 1 to establish conduction with the flat conductor 1, and as shown in FIG. The flat cable connection portion 9 is formed by bending the tip end of the crimp piece 8 that has penetrated through the wire into an arc shape and fixing it by caulking. The connection terminals 5 are formed by crimping pieces 8 projecting from both sides in the width direction of the plate-shaped terminal portion 7 as shown in the figure.

This method has come to be used as a so-called modular wiring which is integrated with a narrow place of a vehicle or a vehicle member such as a ceiling, a door or a dashboard of the vehicle.

[0006]

As described above, in the connection method by crimping or pressure welding, a quality control method for judging the suitability of each connection has been established. In the piercing connection method of piercing the crimp piece 8 of the connection terminal 5 with the flat conductor 1 with respect to the connection terminal 4, particularly the piercing connection method of the small connection terminal 5, the connection device is subjected to various experiments and long-term durability tests. Although various methods have been devised for the connection method and the method of connection, the method of judging the quality of each connection in the mass production process has not been established, and connection failure detection based on the analysis of the load behavior in the connection process of connection terminals The emergence of a method is awaited.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for detecting a connection failure between a flat cable and a connection terminal, which can detect a connection failure based on an analysis of a load behavior in a connection terminal connection process.

[0008]

SUMMARY OF THE INVENTION The present invention provides a flat cable in which a flat conductor is covered with a flat insulating coating.
A method for detecting a connection failure between the flat cable and the connection terminal, which detects a connection failure between the crimp piece and the flat conductor when the flat cable and the connection terminal are connected to the flat cable that pierces the crimp piece of the connection terminal and conducts to the flat conductor. It is an improvement.

In the method for detecting a connection failure between a flat cable and a connection terminal according to the present invention, the piercing load of the crimp piece with respect to the amount of piercing displacement of the crimp piece when piercing the flat cable is measured, and the maximum piercing is performed. The minimum piercing load in the displacement area after the load is
The connection between the crimp piece and the flat conductor is judged to be appropriate or not by comparing with the minimum piercing load in a normal state.

According to such a method for detecting a connection failure at the time of connection between a flat cable and a connection terminal, a flat conductor, which is a defective connection state peculiar when a crimp piece of a connection terminal is pierced and connected to a flat cable, is used. Insufficient contact load of the crimp piece, clogging of the crimp piece receiving groove of the cable receiving bracket that receives the flat cable when piercing the crimp piece, and failure such as buckling of the crimp piece use the fact that the minimum piercing load changes immediately, In the mass production process, the quality of each connection can be determined. In addition, by grasping a change in the minimum piercing load of the worn cable receiving member, the life state of the cable receiving member can be detected.

[0011]

1 and 2 show an example of a method of forming a flat cable connection portion 9 by connecting a connection terminal 5 to a flat cable 4. FIG.

FIGS. 1 and 2 show a connection in which each crimp piece 8 of a connection terminal 5 is connected to a narrow flat conductor 1 of a flat cable 4 through two steps, a first step and a second step. It is each longitudinal sectional view which showed the method.

In forming the flat cable connecting portion 9, as shown in the figure, a cable receiving fitting 1 having a crimp piece receiving groove 10 and a caulking groove 11 provided at different positions on the surface.
2 is used.

In the first step, as shown in FIG. 1, the flat cable 4 is arranged on the cable receiving fitting 12 such that the flat conductor 1 is present on the crimp piece receiving groove 10, and Correspondingly, the plurality of crimp pieces 8 of the connection terminal 5 are arranged downward on the flat cable 4, and while the descent is guided by the guide member 14 by the anvil 13, the connection terminal 5 is pressurized to form the plurality of crimp pieces 8. The crimp piece 8 is pierced into the flat cable 4 to be electrically connected to the flat conductor 1, and the tip of each crimp piece 8 penetrating the flat cable 4 is received by the crimp piece receiving groove 10. At this time, the continuity between the flat conductor 1 and the crimp piece 8 is determined by the extension 1a of the flat conductor 1 that is extended when the crimp piece 8 pierces.
Is obtained by pressurized contact between the crimping piece 8 and

Next, the cable receiving fitting 12 is lowered in the direction of arrow A, and the tip end of each crimp piece 8 penetrating the flat cable 4 is removed from the crimp piece receiving groove 10, and the cable receiving fitting 12 is moved in the direction of arrow B. And each crimp piece 8
The cable receiving fitting 12 is raised in the direction of arrow C so that the crimping groove 11 is fitted to the tip of each crimp piece 8.

In the second step, as shown in FIG. 2, the tip of each crimp piece 8 is fixed to the crimping groove 1 of the cable receiving fitting 12.
1 and the connection terminal 5 with the anvil 13 described above.
Is pressed, the tip of each crimp piece 8 is bent in an arc shape by the caulking groove 11 and caulked to prevent it from falling off.

When the width of the flat conductor 1 of the flat cable 4 is as narrow as about 1.5 mm to 2.0 mm, each crimp piece 8 of the connection terminal 5 is formed as shown in FIG. The terminal width W is designed to be narrower than the width of the flat conductor 1.

The quality of the contact between the crimp piece 8 and the flat conductor 1 when the flat cable 4 is connected in this manner is determined by the contact load between the crimp piece 8 and the flat conductor 1, that is, the first contact in FIG. In the process, the crimping piece 8 pierces the flat conductor 1, and the contact holding load at the contact portion between the extension portion 1 a where the flat conductor 1 extends and the crimping piece 8, in other words, the crimping piece 8 described later pierces the flat cable 4 and It has been found that the resistance largely depends on the resistance load after the opening is formed.

FIG. 3 is a schematic configuration diagram showing an example of an embodiment of a crimp piece piercing and caulking device according to the present invention, which can detect a connection failure when a flat cable is connected to a connection terminal.

In this crimp piece piercing and caulking device, the anvil 13 is pushed down by the anvil lifting press 15, and the connection terminal 5 is pushed down by the lowering of the anvil 13, and the crimp piece 8 is attached to the flat cable 4 supported by the cable receiving fitting 12. The crimping piece 8 penetrates through the flat conductor 1 to penetrate the flat conductor 1 to establish electrical continuity, and the tip of the crimping piece 8 that has penetrated the flat cable 4 is received in the crimping piece receiving groove 10. Next, the cable receiving fitting 12 is lowered by the cable receiving elevating press 16, the tip of the crimp piece 8 is removed from the crimp piece receiving groove 10, and the cable receiving fitting 12 is horizontally moved by the fitting groove switching cylinder 17 to be crimped. Groove 11 to crimp piece 8
So that it faces the tip of In this state, the cable receiving fitting 12 is lifted by the cable receiving elevating press 16, and the crimp pieces 8 penetrating the flat cable 4.
Into the crimping groove 11, and press the anvil lifting press 15
The anvil 13 is pushed down, and the connection terminal 5 is pushed down by the lowering of the anvil 13, the tip of the crimp piece 8 is crimped in an arc shape in the crimping groove 11, and the crimp piece 8 is fixedly fixed to the flat cable 4.

The anvil lifting press 15 is provided with a load cell 18 for measuring a load for piercing the crimp piece 8 into the flat cable 4. A rod displacement detection sensor 1 is provided near the moving direction of the anvil lifting press 15.
9, the displacement of the anvil lifting press 15;
That is, the downward displacement of the crimp piece 8 can be measured.

The load and the electric signal of the displacement detected from the load cell 18 and the rod displacement detecting sensor 19 are inputted to a personal computer 20 and the monitor 21 displays the change of the piercing load with respect to the displacement of the crimp piece 8. At the same time, the minimum piercing load in the displacement area after the maximum piercing load is compared with the minimum piercing load in a normal state to determine whether the connection state between the crimp piece 8 and the flat conductor 1 is appropriate.

In this embodiment, the load cell 1 is used as an output sensor.
Although the sensor 8 and the rod displacement detection sensor 19 are used, other sensors such as a piezoelectric transducer, a capacitance element, and a bottom dead center displacement sensor may be used.

FIG. 4 is a diagram showing a load measured when six crimp pieces 8 pierce the flat cable 4 and penetrate the flat cable 4 with the crimp piece 8 in FIG. In this measurement, a flat cable 4 having a thickness of 0.15 mm and a width of 1.5 mm of the flat conductor 1 and a connection terminal 5 having a terminal width W of 1.2 mm are used.

Here, the load S 1 is the maximum piercing load required for the crimp piece 8 to pass through the flat cable 4. S2 is a conductor opening resistance when the crimping piece 8 penetrates through the flat cable 4 and tears and opens the flat conductor 1. As shown in FIGS. 5A and 5B, the tip of the crimping piece 8 is pushed down. Stroke position k
1, an opening H having a width of 2t1 is formed in the flat conductor 1. After that, even if the tip of the crimp piece 8 moves by the same moving distance to reach the stroke position k2, the opening H remains at t1> t2.
The opening H does not spread and increase as much as the width at the position k1. Therefore, in FIG.
After the maximum load is applied until the conductor penetrates, the conductor opening resistance S2 is reduced temporarily to the frictional resistance S3 of the crimp piece 8 after the conductor penetrates, and the minimum height of the conductor opening resistance S2 is the maximum. This corresponds to the minimum stab load in the displacement area after the stab load. When the minimum piercing load is equal to or less than the buckling threshold value of the crimp piece 8 and is equal to or more than a predetermined load, a stable connection between the crimp piece 8 and the flat conductor 1 after crimping is obtained. And thermal shock test after connection.

Actually, in the combination of the flat cable 4 and the crimp piece 8 described above, 150 N or more and 220
A minimum piercing load of less than N is used as a criterion for determining a good product. Therefore, by measuring the minimum load in the displacement area after the maximum piercing load S1, the pass / fail judgment can be made in comparison with the non-defective product minimum load area.

FIG. 6 is a diagram showing actual measurement of the piercing load with respect to the amount of piercing displacement of the crimp piece 8 in various connection situations.

Sample A is a piercing load in the normal state described in FIG. 4, and the minimum load M1 is about 180N.

In the sample B, the crimp piece 8 was not accurately pushed down into the crimp piece receiving groove 10, or the crimp piece 8 pierced in a state where the gap g in FIG. In this case, the contact load between the extended portion 1a of the flat conductor 1 and the crimp piece 8 decreases, and the minimum load in FIG. 6 appears as M2.

In the sample C, insulating scum and foreign matter are interposed between the crimp piece receiving groove 10 and the flat cable 4,
Although the crimp piece 8 penetrated the flat cable 4,
This is a piercing load when the contact load between the extending portion 1a of the flat conductor 1 and the crimp piece 8 in FIG.

The sample D is caused by the inclusion of foreign matter in the crimp piece receiving groove 10, the abnormality of the crimp piece receiving groove 10, and the abnormality of the thickness of the flat conductor 1 or the flat insulating coating 2.
This is the piercing load when the crimp piece 8 cannot penetrate the flat cable 4 and the crimp piece 8 buckles.

As described above, various abnormal states occurring in the connection between the flat conductor 1 and the crimp piece 8 can be easily detected by utilizing the behavior of the piercing load of the crimp piece 8 peculiar to the flat cable 4 and the connection terminal 5. can do.

In the above example, the flat cable 4 has a structure in which the flat insulating coating layer 2 is bonded to both sides of the flat conductor 1 via the adhesive layer 3, but the flat insulating coating layer 2 is provided by extrusion coating. You can also.

[0034]

According to the method for detecting a connection failure between the flat cable and the connection terminal according to the present invention, the piercing load of the crimp piece with respect to the piercing displacement of the crimp piece when the crimp piece is pierced into the flat cable is measured. Since the minimum piercing load in the displacement area after the maximum piercing load is compared with the minimum piercing load in a normal state, it is determined whether or not the connection state between the crimp piece and the flat conductor is appropriate.
Insufficient contact load of crimping piece to flat conductor, crimp piece receiving part of cable receiving fitting to receive flat cable when piercing crimping piece, which is a specific poor connection state when piercing crimping piece of connection terminal to flat cable The defect such as clogging of the groove and buckling of the crimp piece can be used to judge the quality of each connection in the mass production process by utilizing the fact that the minimum piercing load changes immediately. In addition, by grasping the change in the minimum piercing load of the worn cable receiving fitting, the life state of the cable receiving fitting can be detected.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view in a first step of a step of connecting a connection terminal to a flat cable to form a flat cable connection portion.

FIG. 2 is a longitudinal sectional view in a second step of a step of connecting a connection terminal to a flat cable to form a flat cable connection portion.

FIG. 3 is a schematic configuration diagram of an example of an embodiment of a crimp piece piercing and caulking device of the present invention that can detect a connection failure when a flat cable is connected to a connection terminal.

FIG. 4 is a diagram showing a load measured when a crimp piece pierces and penetrates a flat cable with the crimp piece piercing and crimping device of FIG. 3 with respect to a displacement amount of the crimp piece.

FIGS. 5A and 5B are a front view of a crimp piece for explaining a phenomenon in which the opening resistance of the flat conductor decreases, and a plan view showing a state where the tip end of the crimp piece is pierced by the flat conductor. is there.

FIG. 6 is a diagram showing actual measurement of a piercing load with respect to a piercing displacement amount of a crimp piece in various connection situations.

FIG. 7 is a sectional view of a main part of an example of a flat cable.

FIG. 8 is a perspective view showing a state before connection terminals are connected to a flat cable.

FIG. 9 is a perspective view of a state after connection terminals are connected to the flat cable.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flat conductor 1a Extension part 2 Flat insulating coating layer 3 Adhesive layer 4 Flat cable 5 Connection terminal 6 Mating connection part 7 Plate-shaped terminal part 8 Crimp piece 9 Flat cable connection part 10 Crimp piece receiving groove 11 Caulking groove 12 Cable receiving Hardware 13 Anvil 14 Guide member 15 Anvil lifting press 16 Cable receiving lifting press 17 Metal fitting groove switching cylinder 18 Load cell 19 Rod displacement detection sensor 20 Personal computer 21 Monitor

Continued on the front page (72) Inventor Kazunori Saka 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. F-term (reference) 2G014 AA14 AB42 AB60 AC07 5E051 JA03 JB09 5G355 AA08 BA01 BA11 CA06 5G375 AA11 CA02 CA13 CC07 DA36 DB09 EA15

Claims (1)

[Claims] 1. A flat cable having a flat conductor coated with a flat insulating coating, wherein the crimp piece and the flat conductor are connected at the time of connection between the flat cable and the connection terminal, the crimp piece of the connection terminal being pierced to conduct the flat conductor. In the method of detecting a connection failure between a flat cable and a connection terminal for detecting a connection failure with the flat cable, a piercing load of the crimp piece is measured with respect to a displacement amount of the crimp piece when the crimp piece is pierced into the flat cable. A flat cable characterized in that the minimum piercing load in the displacement region after the maximum piercing load is compared with the minimum piercing load in a normal state to determine whether or not the connection state between the crimp piece and the flat conductor is appropriate. Connection failure detection method when connecting to the connection terminal.